<!DOCTYPE html>
<!-- 文件类型声明 -->
<html lang="en">
<head>
    <meta charset="UTF-8">
    <!-- 设置字符集编码格式，防止乱码 -->
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <!-- 单标签 -->
    <title>第一个网页</title>
    <!-- 设置网页标题 -->
</head>
<body>
    today is my first html.
</body>
</html>